Some questions about Crossfire

Hey guys. I've always been of the mindset of get a single powerful card over a dual card set up, so I'm a total Crossfire/SLI virgin.

I'm planning on going with the gigabyte R9 270X OC and planning on adding another in at a later time. If I could afford a much better card I'd go for a single 280X but unfortunately that just won't be the case. My question is, would it be worth it? Or would there just be too many problems. Also am I safe in assuming that the FX-8350 wouldn't bottleneck it unless playing a CPU intensive game? And lastly would a 750W psu be enough to cover the power draw?

I would like to play next gen games at least at 1080p on Ultra. I know that a 270x won't handle that, at least not for long. I'm also kinda concerned about the 2GB limit. I'd like to try out eye infinity at some point but would the VRAM be a bottleneck or would Crossfiring help avoid that?

Edit: The motherboard that this rig will be running on is http://www.newegg.ca/Product/Product.aspx?Item=N82E16813131851 (x16, x16)